This disclosure is generally directed to layered imaging members, photoreceptors, photoconductors, and the like. More specifically, the present disclosure is directed to multilayered flexible, belt imaging members, or devices comprised of an optional supporting medium like a substrate, a silanol, such as a hydrophobic silanol containing a photogenerating layer, and a charge transport layer, including a plurality of charge transport layers, such as a first charge transport layer and a second charge transport layer, an optional adhesive layer, an optional hole blocking or undercoat layer, and an overcoating layer, and optionally wherein at least one of the charge transport layers contains at least one charge transport component, a polymer or resin binder, a silanol, and an optional antioxidant. Moreover, at least one of the charge transport layers can be free of a silanol; in embodiments the photogenerating layer contains a silanol, and the charge transport layers are free of a silanol; and in embodiments the charge transport layer contains a silanol, and the photogenerating layer is free, that is this layer does not contain a silanol. Additionally, in embodiments a metal dialkyldithiophosphate, such as a zinc dialkyldithiophosphate (ZDDP) can be included in the photogenerating layer or charge transport layer, and wherein each of these layers are free of a silanol.
The photoreceptors illustrated herein, in embodiments, have excellent wear resistance, extended lifetimes, elimination or minimization of imaging member scratches on the surface layer or layers of the member, and which scratches can result in undesirable print failures where, for example, the scratches are visible on the final prints generated. Additionally, in embodiments the imaging members disclosed herein possess excellent, and in a number of instances low Vr (residual potential), and allow the substantial prevention of Vr cycle up when appropriate; high sensitivity; low acceptable image ghosting characteristics; low background and/or minimal charge deficient spots (CDS); and desirable toner cleanability. More specifically, there is illustrated herein in embodiments the incorporation of suitable silanols in an imaging member, which silanols can be included in at least one charge transport layer, the photogenerating layer, or in both the at least one charge transport layer and the photogenerating layer. At least one in embodiments refers, for example, to one, to from 1 to about 10, to from 2 to about 7; to from 2 to about 4, to two, and the like. Moreover, the silanol can be added to the at least one of the charge transport layers, that is for example, instead of being dissolved in the charge transport layer solution, the silanol can be added to the charge transport as a dopant, and more specifically, the silanol can be added to the top charge transport layer. Similarly, the silanol can be included in the photogenerating layer dispersion prior to the deposition of this layer on the substrate. When the silanol is mixed or milled with photogenerating components, while not being desired to be limited by theory, it is believed that the silanol reacts with the photogenerating pigment rendering such pigment hydrophobic and improves the dispersibility of the pigment in a polymer binder via interactions between the binder and the pigment. The hydrophobic silanols selected are stable in that, for example, the Si—OH groups eliminate water to form siloxane (Si—O—Si) linkages primarily because of the hindered structures of the three other bonds attached to the silicon. Thus, for example, the silanols are stable for extended time periods, such as for example, indeterminately long shelf lives like three years in embodiments.
Also included within the scope of the present disclosure are methods of imaging and printing with the photoresponsive or photoconductive devices illustrated herein. These methods generally involve the formation of an electrostatic latent image on the imaging member, followed by developing the image with a toner composition comprised, for example, of thermoplastic resin, colorant, such as pigment, charge additive, and surface additive, reference U.S. Pat. Nos. 4,560,635; 4,298,697 and 4,338,390, the disclosures of which are totally incorporated herein by reference, subsequently transferring the image to a suitable substrate, and permanently affixing the image thereto. In those environments wherein the device is to be used in a printing mode, the imaging method involves the same operation with the exception that exposure can be accomplished with a laser device or image bar. More specifically, flexible belts disclosed herein can be selected for the Xerox Corporation iGEN3® machines that generate with some versions over 100 copies per minute. Processes of imaging, especially xerographic imaging and printing, including digital, and/or color printing, are thus encompassed by the present disclosure. The imaging members are in embodiments sensitive in the wavelength region of, for example, from about 400 to about 900 nanometers, and in particular from about 650 to about 850 nanometers, thus diode lasers can be selected as the light source. Moreover, the imaging members of this disclosure are useful in high resolution color xerographic applications, particularly high speed color copying and printing processes.